It is well known for mechanical-thermal structures comprising heat pipes to be used to cool heat-dissipating devices. A heat pipe containing a coolant recovers the heat released by a dissipating device at one of these ends, the coolant evaporates and condenses at the other end, releasing the heat to the mechanical-thermal structure, which dissipates it into the ambient environment; in this case, the ambient environment is space.
According to the prior art, heat pipes are realized using the same materials as the mechanical-thermal structures in which they are integrated. This kind of strategy avoids the problems associated with different expansion coefficients, which produce zones of mechanical stress which risk damaging the structure. However, this strategy limits the choice of materials, which affects the performance of the device making up the mechanical-thermal structure in terms of mass. Moreover, the production of mechanical-thermal structures is based on standard manufacturing methods such as machining, milling, adhesive bonding or screwing. This kind of standard production necessitates a large number of parts which are complex to assemble and require manufacturing constraints which are difficult to observe. The devices produced in this way have an increased mass and are particularly costly.
U.S. Pat. No. 6,065,529 proposes a first solution involving the realization of a channel in the mechanical-thermal structure intended to receive a heat pipe. The inside dimensions of the channel are greater than the outside dimensions of the heat pipe, thereby leaving a gap between the inside wall of the channel and the outside wall of the heat pipe, said gap being filled with a heat conductive fluid or metal powder. The gap between the inside wall of the channel and the outside wall of the pipe thereby allows the material from which the heat pipe is made to expand and contract without generating mechanical stresses on the materials of the mechanical-thermal structure.
The advantage of this first solution is that it solves the problems associated with differences in the thermal expansion coefficient of the materials, which allows greater latitude in relation to the choice of materials used. However, this solution does not solve the problems involved in producing the mechanical-thermal structure in terms of cost.